the home of the turntable

DP-62L tracking problem

deeply dp

DP-62L tracking problem

Postby organtec » 28 May 2018 17:53

I have a Denon DP-62L turntable which occaisonally skips. The settings for tracking force, anti-skating, and Q damping are correct. I have tried different settings with no Help.With a blank record with no grooves sometimes the stylus will cue down and stay at that point. At times the arm will move either in or out and try to correct itself to the original cue point. The lifter is not interfering with the arm. The records concerned do not skip on my two other turntables. It does not always exhibit this error always in the same place. do all servo arms do this? Keith
organtec
 
Posts: 2
Joined: 14 Sep 2010 11:46
Location: vermont

Re: DP-62L tracking problem

Postby captmark » 29 May 2018 10:33

Are you running a particularly light VTF? Does zeroing out the anti-skate and Q-damping make a difference? If not your issue is most likely the arm bearings need re-lubed. There are upper and lower bearings you can not see or get to when the arm is installed.

A quick test to see if this is the case; find a record that you have this issue on. Note a particular section where this occurs. Turn the power off and remove the arm wand. You may want to tighten down your counterweight to keep from having to reset your VTF. Grabbing the top of the arm base at the pivot point and keeping the base from smacking the lifter bar twist the arm back slowly just a time or two at first to see if you feel any slight resistance and where you do in the travel. Noting how easily it moves now twist it back and forth very quickly for 5-10 seconds or so-go the full travel of the arm, you won't hurt anything that isn't already hurt. Reinstall the wand, double check and duplicate your previous VTF and play the record again all the way through.

If this fixes your problem (temp) or moves the skipping to a different part of the record you need to relube those bearings. The only way to do so is to pull the arm. If you're going to do that you might as well plan on changing the CDS sensors and the counterweight tube support screw if it is sagging while you're there- they're $2 parts and two minutes to change once you're in there. The bearings are not a job for the faint of heart, but it is not impossible and needs an attention to detail to mark and reinstall parts in exactly the same spots so that sensors and op amps work properly. You'll need a solder iron, philips screwdriver and one allen wrench....and some good synthetic lube. I do it on every Denon table I restore (no I don't do outside repairs) and I can do one in about 30-40 minutes without interruptions. My first one took almost a whole evening mostly because you HAVE to reinstall the shutter and horizontal the exact way they came out or the arm is stuck or the anti skate doesn't work or the arm no longer lifts at the end or... A camera phone and a sharpie would've been a godsend, but I guess I'd never heard of those things till after that day... :-)
captmark
member
member
 
Posts: 107
Images: 4
Joined: 18 Sep 2012 07:13

United States of America

Re: DP-62L tracking problem

Postby organtec » 19 Jun 2018 12:59

it isn't bearings or hang up with lifter bar. When stylus is set down on an uncut or no groove album sometimes it will stay right where it should. other times it will skate either inwards or outwards then make an opposite movement then back and forth trying to set itself at the original set down point. Where i set it down initially doesn't matter.
organtec
 
Posts: 2
Joined: 14 Sep 2010 11:46
Location: vermont

Re: DP-62L tracking problem

Postby EdAInWestOC » 19 Jun 2018 19:40

I bought my DP-62L new in 1983 and have used it continuously until 2 years ago when it was boxed up and put into storage.

The Denon tonearm on the DP-62L is an electromagnetic thing that corrects for resonances and is supposed to make tracking records a better experience. If you do not have any bearing issues and there are no physical limitations then I believe your problem will be in the electronics that govern your tonearm's movement.

Unless you have had your DP-62L recapped you are likely looking at a symptom of old, out of spec electrolytic capacitors. Some people say amusing things like "check for bulging caps" and other such rudimentary stuff.

The truth is that electrolytic caps can fail without showing any signs at all. The electrolytic paste inside the aluminum can is most likely dryed up and the value of the capacitor is way out of tolerance for the circuit.

The problem with electrolytic caps going out of spec is that the symptoms will be all over the place. It can manifest itself as anything that the turntable does. You can do everything, including shaking fairy dust over the table, but nothing will make that table reliable again until you invest in a complete recapping of the circuitry.

If you really want to keep the turntable, then its pretty much a no-brainer. Go ahead and invest in a recap of the electrolytic capacitors. If you are not sure what you are going to do with the table, then consider the cost of a recap job and make your decision.

It depends on the technician. There are less than 40 electrolytic capacitors in the entire turntable and the cost for those parts is around $40 USD for good quality replacement caps. If you are handy with a soldering iron, you have an easy answer.

It won't take very long if you have the right gear to desolder the old caps and solder in the new ones. The job can be done in one evening without too much trouble or you can take your time and stretch it over 2 or more sessions.

One note if you are doing the recap yourself. The Denon PCB is somewhat sensitive to lifting traces if you over-heat your solder joints. Just be quick and apply only enough heat to do the job.

If you are going to let a technician do the job, I personally wouldn't pay more than $200 USD for the whole thing. An experienced tech can do the job in a couple of hours and, like I said above, the parts are not expensive.

Its a good turntable and it is worth holding onto. It is your decision.
Ed

PS. captmark mentioned relubing the bearings and I agree. The tonearm bearings and the turntable main bearing are called lifetime bearings but "lifetime" is a fairly loose term.

Denon did not foresee someone using the 62L 3 decades later and no matter how good the lube is, it won't last 30+ years. The bearings need to be opened up, cleaned and re-lubed. It is an ear opening experience but there is an audible difference when you service an old main bearing.

My DP-62L was well maintained and well treated but after 30+ years of service, my main bearing had to be re-done. I had to have my thrust plate and ball replaced. Plus I had to have the surrounding metal parts machined to restore the tolerances that were originally in the Denon main bearing.

Not all 62Ls will need the same attention, but more need it than people suspect. My main bearing was making a thumping sound at 33 RPM but was quiet at 45 RPM. It was a worn thrust plate, ball and the metal parts were worn. Not all main bearings are worn in the same fashion and can just add noise to your playback...not thumping but a more constant noise that can be ignored if you are not aware.

My resulting main bearing is a beautiful jeweled ceramic bearing that outperforms the original Denon bearing. The expert who did this work is sadly, no longer with us. He was a friend who passed away a few years ago.

I miss him personally and the turntable world is worse off without such expertise. Unfortunately I cannot recommend another source for bearing work.
EdAInWestOC
long player
long player
contributor
 
Posts: 1284
Images: 73
Joined: 03 Feb 2004 02:39
Location: Glen Burine, MD USA

United States of America

Re: DP-62L tracking problem

Postby captmark » 19 Jun 2018 20:22

I agree with Ed. You haven't mentioned if turning off the servo control or moving the dial while the arm is playing on a record makes a difference, or if that difference changes with time, but I highly recommend you stop using that table while you determine if you want to do the recap. They don't fix themselves, and if it actually has periods of time where it is working correctly then I would hope you haven't got any permanent damage yet. You "could" open the bottom up, pull the pots for the anti skate and servo and clean them - again the fact it seems you're saying that turning the knobs off or up all the way off makes no difference could mean they are dirty - but ultimately you are postponing the inevitable. Just make sure you do the pots as part of your recap and refresh.
captmark
member
member
 
Posts: 107
Images: 4
Joined: 18 Sep 2012 07:13

United States of America

Return to Denon